Creatine Kinase (CK), Total

Test Code

374

CPT Codes
82550

Preferred Specimen

1 mL serum collected in a SST (red-top) tube

Minimum Volume

0.5 mL

Other Acceptable Specimens

Plasma collected in: Sodium heparin (green-top) or lithium heparin (green-top) tube

Instructions

If CK and CK Isoenzymes are ordered together, specimen must be submitted frozen

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 72 hours
Refrigerated: 7 days
Frozen: 28 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis • Anticoagulants other than heparin

Methodology
Spectrophotometry (SP)

Setup Schedule

Night Sets up 3 days a week.

Report Available

Reports in 3 to 4 days.

Clinical Significance

This test measures creatine kinase (CK), an enzyme found primarily in striated muscle and heart tissue, and may be useful in assessing muscle damage.

CK is a dimeric enzyme composed of either 2 B subunits (CK-BB), 2 M subunits (CK-MM), or an M and a B subunit (CK-MB). CK-MM is the primary isoenzyme found in the skeletal muscle and heart tissue. CK-BB is mainly found in the brain and smooth muscle of gastrointestinal tract and urinary bladder. CK-MB is mainly found in the heart with a small amount in skeletal muscle [1]. An elevated level of any isoenzyme results in an elevated total CK level.

An increase in the CK level is often observed in inflammatory myopathy (eg, viral myositis, polymyositis, and immune-mediated myopathies), muscular dystrophy (eg, Duchenne sex-linked muscular dystrophy), rhabdomyolysis, or malignant hyperthermia [1]. In patients with neuromuscular disorders, an increased CK level may be the only initial manifestation [1]. Increased CK activity may also be caused by hypothyroidism, acute myocardial infarction, chronic renal failure, direct muscle trauma (eg, surgery and intramuscular injection), excessive exercise, certain medications (eg, statins, fibrates, antiretrovirals, and angiotensin II receptor antagonists), or brain damage or very low birth weight in newborns [1].

The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.

Reference
1. Panteghini M, et al. Serum enzymes. In: Rifai N, et al. eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elservier Inc; 2022:4149-4299.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.